This is a passage on living healthily. The writer suggests if one wants to live longer, he remind himself that "Don't leave poisons in the medicine cabinet where "sleepy" hands can find them in the night; don't daydream while crossing the street; when driving a car, don't drive at excessive speed."

It's easy to understand the latter two pieces of advice, but I don't see the meaning of "poisons" and "sleepy hands". Looking forward to your notes. Thanks!

'Poisons' here is shorthand for 'poisonous substances [in containers]' - i.e. any substance that could cause harm if eaten or swallowed.

'Sleepy' is a 'transferred epithet'. It really describes the people who have the 'hands'. The sense of the clause is 'Don't leave poisonous substances in the medicine cabinet where sleepy people can pick them up and eat or swallow them by mistake in the middle of the night'.

Thank you MrPedantic. Your note is truly helpful. Please allow me to ask one more question, why would people keep poisonous subtances in the cabinet? What would they be? Would you please give me an example of the poisonou stuff that people might keep in their house (maybe necessarily)? Thank you again!